There's more to the platform wars than mobile - Android is starting to take off in non-mobile markets in a massive way - Internet of Things, Television (Chromecast), etc. To date Linux has been the dominant OS but Android is now taking some embedded designs which would have run Linux. The effective decoupling of Android from carriers for non-mobile markets + the richness of tools and the existing developer ecosystem will likely cement Android as the definitive open source OS of the next decade. This will have pluses for Google but also unintended consequences.

A common misconception among people who don't really understand what Linux is - one that I'm seeing pop up more and more now that people are trying to paint Android in a negative light - i.e., as competition to not just iOS, but also the noble and open source Linux.

Repeat after me: Android is just as much 'Linux' as Ubuntu, Debian, Red Hat, or anything else that uses the Linux kernel. Technically, a better term would be 'Linux distribution', since Linux in and of itself is just a kernel. Wikipedia defines 'Linux distribution' quite well:

A Linux distribution (often called distro for short) is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications. These operating systems consist of the Linux kernel and, usually, a set of libraries and utilities from the GNU Project, with graphics support from the X Window System. Distributions optimized for size may not contain X and tend to use more compact alternatives to the GNU utilities, such as BusyBox, uClibc, or dietlibc.

Android is a Linux distribution, and is an addition to the Linux ecosystem - not a challenger. Painting it as such is just a sign of ignorance.

Suddenly all the work RMS did to properly prefix system with "GNU" makes sense. GNU/Linux is as much Linux as Android/Linux. We need to clearly state _which_ Linux we are talking about.

Except that Stallman is just sore about how, with all the effort he put into GNU, Linux got all the glory. GNU is a relatively small portion of the codebase these days and GCC is most of that. By his logic, it should always be called (at minimum) "X11/GNU/Linux", spoken as "X11 on GNU on Linux".

(It's one reason I'm glad things like LLVM are slowly squeezing the remaining "fewer LOCs than X11" of GNU out of Linux distros. It'll end this pointless nomenclature argument.)

Hence why people use "Android" to refer to the Java-centric, bootloader-locked platform with the "incomplete but liberally licensed" libc and "Linux" to refer to the ABI of the X11+glibc+Linux stack which usually also comes with the rest of the GNU userland.

As long as your glibc replacement is good enough to meet the needs of the applications you're running on it, the use or non-use of a GNU userland has little to no effect on the "Linux" ABI.

The ABI we care about is more correctly named "X11/Linux" if we're going by Stallman's "GNU on Linux" pronunciation. In fact, if you look at build identifier strings (or similar things like browser User-Agent strings), that's how it's identified.

That's the way I've always seen it; Android is the userland, Linux is the kernel.

However, the kernel used in Android --especially of late-- is heavily modified from the stock Linux kernel, particularly compared to other mobile Linux-based platforms like Maemo and WebOS. This is not a complaint or negative criticism, just pointing it out.

Actually, no, saying that Android is not Linux is not at all like saying that a Rolls Royce is not a car.

Unless you are going to make up a new definition of the word "Linux" then it refers to one of two things (I think two things are already enough).

The first thing that "Linux" can mean is the kernel (you can argue that technically this is the only meaning). In that context an operating system is more than its kernel. Saying that Android is Linux would be like saying that a car is an engine. Obviously a car is not an engine, though a working car will contain an engine. So in this sense Android is not Linux.

The second thing that "Linux" can refer to is the operating system that has been popularized under the term "Linux." Android is a different operating system than the operating system known as Linux, so in this sense also Android is not Linux. To continue with the analogy, if you take a Jeep and put a Ford engine or a Chevrolet engine in it (both of which I have seen done), it doesn't turn the Jeep into a Ford or a Chevy.

You can run openoffice and all those other tools on android with no problem. The only difference is that android doesn't include the same set of userland libraries as typical linux distros do, so you'd have to install them yourself if you want to run them on an android system.
You can even take an entire standard linux distro like ubuntu or debian, and run it inside of a chroot on an android phone.

Since both a car and a boat can use the same engine, you can build an amphibious vehicle that uses that engine. That amphibious vehicle is both a car and a boat. That, however, does not make all cars into boats or all boats into cars.

Similarly, the fact that any Android operating system can be made into both a GNU/Linux and an Android operating system or that any GNU/Linux operating system can be made into both an Android and a GNU/Linux operating system does not make Android and GNU/Linux the same operating system.

Try running a couple software which you can run without trouble in any conventional linux distribution. Open office? Gimp? Nano? Vim?

There are embedded Linux distros where you can't run those programs either so I guess they're not Linux?
Conversely, all of those programs run on Windows so...Windows is Linux?
Linux is a kernel, not an operating system. Android is using the Linux kernel so it's a Linux-based operating system.

There are embedded Linux distros where you can't run those programs either so I guess they're not Linux?

I bet most of them contain BusyBox, which is basically a stripped down GNU toolchain packed into one little embedded-device-friendly executable file, offering nearly complete traditional UNIX/Linux shell functionality. And even then, some embedded distros designed for more capable embedded devices may go all the way and have the actual, complete GNU toolchain.

But yeah; to be fair, in this case, the reason you can't run an complete office suite or an image editor is more a result of the weakness and lack of resources than the OS itself. No one in their right mind would even attempt to fire up the GIMP or even just X.org on a WRT54GL or something even remotely similar, and the Linux-based firmware it uses is most definitely not the main bottleneck of such a system.

Absolutely. What does it help anyone if somewhere down below Android is Linux. If you can't run any linux desktop apps on it and you can't run any Android apps on desktop linux then they are incompatible!